SL-11315 Viewer asks to play media and retains selected choice

indra/llui/llnotifications.cpp

indra/llui/llnotifications.h

indra/newview/CMakeLists.txt

indra/newview/app_settings/settings.xml

indra/newview/llappviewer.cpp

indra/newview/llfloaterpreference.cpp

indra/newview/llfloaterpreference.h

indra/newview/llpanelnearbymedia.cpp

indra/newview/llpanelvolumepulldown.cpp

indra/newview/llstartup.cpp

indra/newview/lltoastalertpanel.cpp

indra/newview/lltoastnotifypanel.cpp

indra/newview/lltoastpanel.cpp

indra/newview/llviewermedia.cpp

indra/newview/llviewermedia.h

indra/newview/llviewerparcelaskplay.cpp

indra/newview/llviewerparcelaskplay.h

indra/newview/llviewerparcelmediaautoplay.cpp

indra/newview/llviewerparcelmediaautoplay.h

indra/newview/llviewerparcelmgr.cpp